Roche became 5th Baron Fermoy in 1955 when his father died. He was an elected member of Newbury District Council between 1976 and 1979. He was chairman of Eddington Bindery Ltd, based at the Fermoy family home near Hungerford. He was also a steeplechase jockey.

Baron Fermoy and his family have close connections to the British royal family. His mother Ruth was a longstanding member of the Queen Mother's household. His sister, Frances, was the mother of Lady Diana Spencer. As the bride's maternal uncle, Lord Fermoy attended her wedding to the Prince of Wales in 1981.

He was suffering from depression for a long period of time. Roche committed suicide by gunshot at his home, Eddington House, in Hungerford on 19 August 1984. He was 45.